In 1755, Thomas Williams and John Cooley make a survey to find a suitable route for a man-made waterway across north Leinster from Dublin to the River Shannon. They originally plan to use a series of rivers and lakes, including the Boyne, Blackwater, Deel, Yellow, Camlin, and Inny and Lough Derravaragh.
Work commences in 1789 and lasts 27 years before finally reaching the River Shannon in 1817, at a total cost of £1,421,954. Construction is unexpectedly expensive and the project is riven with problems. In 1794 the Royal Canal Company is declared bankrupt. The Duke of Leinster, a board member, insists that the new waterway take in his local town of Maynooth. The builders have to deviate from the planned route and necessitate the construction of a ‘deep sinking’ between Blanchardstown and Clonsilla. The diversion also calls for the building of the Ryewater Aqueduct, at Leixlip.
The canal passes through Maynooth, Kilcock, Enfield, Mullingar and Ballymahon has a spur to Longford. The total length of the main navigation is 145 kilometres (90 miles), and the system has 46 locks. There is one main feeder, from Lough Owel, which enters the canal at Mullingar.
In 200 years it has been maintained by eight successive agencies – the Royal Canal Company, the Commissioners of Inland Navigation, the New Royal Canal Company, Midland Great Western Railway Company, Great Southern Railways, CIÉ, and the Office of Public Works.
The canal falls into disrepair in the late 20th century, but much of the canal has since been restored for navigation. The length of the canal to the River Shannon is reopened on October 1, 2010, but the final spur branch of the canal to Longford Town remains closed.
(Pictured: Royal Canal as it enters Dublin city centre (left) and Royal Canal in rural County Westmeath north of Kinnegad (right)